Enclosed commercial mall. Each use in an enclosed commercial mall shall be entitled to one sign per business to be displayed on the exterior of the building containing the use. Such signs shall be uniform in height, lettering size, style, color, and height above the ground. The total area for all tenants' signs shall not exceed one square foot for each linear foot of building frontage, not to exceed a maximum of 50 square feet. The landowner shall be responsible for submitting the request for the signs. When there is a change in occupancy, a permit shall not be required to change an existing commercial mall sign, provided such sign is not changed in height, lettering size, style, color and height above the ground.